At present, the research on the sintered porous materials mainly focuses on several aspects of the optimization of preparing processes, the investigations on pores-forming mechanisms, the improvement of material properties and the expansion of application ranges, wherein, as for the pores-forming mechanisms, the pores-forming means applied to the method for preparing the sintered porous materials mainly comprises: firstly, pores formed by chemical reactions, the mechanism of which is on the basis of the partial diffusion effect caused by the larger differences in the intrinsic diffusion coefficients of different elements, thereby resulting in generating the Kirkendall pores in the materials; secondly, pores formed by the physical accumulation of raw materials particles; and thirdly, pores formed by the escape of additives. The select and combination of the pores-forming means described above would directly and inevitably affect the pore structure of the porous materials. The pore structures of the porous materials would further determine the properties of the porous materials. Thus, the sintered porous materials generated on the basis of different pores-forming means always have different pore structures and using performances, and these porous materials can be identified and characterized more clearly by understanding and measuring the pore structures and use performances. At present, in order to adequately characterize the porous materials, it is usually adopted in the art of: 1) compositions and contents of the raw materials; 2) pore structure parameters, mainly comprising porosity, pore diameter and so on; 3) material properties, comprising permeability, mechanical strength and chemical stability, wherein, the permeability is usually measured by a fluid permeation method, the mechanical strength is usually characterized by tensile strength, and the chemical stability is mainly characterized by acid resistance and/or alkali resistance.
A Ti—Al intermetallic compound porous material is a sintered inorganic porous material between high temperature alloys and ceramics. It is bonded together by metallic bonds and covalent bonds and has common advantages of both metal materials and ceramic materials, thus, the Ti—Al intermetallic compound porous material has broad application prospects as a filter material. It is generally acknowledged that the Ti—Al intermetallic compound porous material has excellent properties; however, the corrosion resistance property in strong acid conditions of the Ti—Al intermetallic compound porous material still needs to be improved. For example, in the condition of keeping temperature at 90° C., when the pH value decreases from 3 to 2, both of the weight loss and porosity of the sample of the Ti—Al intermetallic compound porous material with the Al content of 35 wt. % increase significantly, and it is indicated that the corrosion resistance of the material reduces significantly. Therefore, for some special application conditions, the corrosion resistance of the material still needs to be further improved. Before the filing date of the present application, the sintered porous material, which is similar to the Ti—Al intermetallic compound porous material having the common features of the metal materials and ceramics materials and also has stronger corrosion resistance at the same time, has not been discovered.